If the changes are intended to be done manually, as opposed to having a regular and predictable form, then it seems extreme overkill to use perl, rather than a normal ftp access to the directory.

Otherwise, for automated changes, perl does not provide off-the-shelf scripts, rather CPAN provides modules to assist the programmer in writing such scripts. In this case, Net::FTP provides an o-o model that is easy to use (provided you know the basics of perl o-o programming).

Update: Some code has arrived in the OP meanwhile, but it could do with some code tags.